CBB eliminates the secret of electrolytic capacitors

Speaking of CBB capacitors, you may have some strangeness, but if you mention electrolytic capacitors, most people will not feel strange. Electrolytic capacitors are widely used and used to be one of the mainstream capacitors, but they are being gradually replaced by CBB capacitors. So why does CBB capacitors gradually begin to replace electrolytic capacitors?

What do the two capacitors mean?

CBB capacitor:

Non-polar, high insulation resistance, excellent frequency characteristics (wide frequency response), and low dielectric loss. Based on the above advantages, the film capacitor is used in a large amount on an analog circuit. In particular, in the part where the signal is connected, it is necessary to use a capacitor having a good frequency characteristic and a very low dielectric loss to ensure that the signal is transmitted without excessive distortion. The dielectric constant is high, the volume is small, the capacity is large, the stability is better, and it is suitable as a bypass capacitor. Polystyrene film capacitors, low dielectric loss, high insulation resistance, but high temperature coefficient, can be used in high frequency circuits.

Electrolytic capacitor features:

Polar electrolytic capacitors usually function as power supply filtering, decoupling, signal coupling, time constant setting, and DC blocking in power supply circuits or intermediate frequency and low frequency circuits. Generally, it can not be used in the AC power supply circuit. When used as a filter capacitor in the DC power supply circuit, the anode (positive electrode) should be connected to the positive terminal of the power supply voltage, and the cathode (negative electrode) should be connected to the negative terminal of the power supply voltage. Otherwise it will damage the capacitor. Non-polar electrolytic capacitors are commonly used in speaker divider circuits, television S correction circuits, and start-up circuits for single-phase motors.

Electrolytic capacitors are widely used in household appliances and various electronic products. Their capacities range from 1 to 1000 μF and rated operating voltages range from 6.3 to 450V. The disadvantage is that the dielectric loss and the capacity error are large (the maximum allowable deviation is +100%, -20%), the high temperature resistance is poor, and the storage time is long and easy to be invalid.

Back to the beginning of the question, why is the electrolytic capacitor eventually replaced by the CBB capacitor? This is because the type of filter has changed. The DC filter uses a polar electrolytic capacitor, and the filtered AC wave uses a non-polar CBB capacitor. When AC waves are used, CBB capacitors are used instead of motor capacitors. Moreover, when the circuit is a high frequency circuit, it is necessary to use a CBB capacitor.

At present, there are more and more applications of AC waves, and more and more devices using AC waves, so people will have the illusion that CBB capacitors gradually replace electrolytic capacitors. In fact, in DC applications, electrolytic capacitors are still inseparable. I hope that after reading this article, you can have a clear understanding of the difference between electrolytic capacitors and CBB capacitors.